1. Field of the Invention
The present invention relates to a printing system including a printing unit and a post-processing unit, etc., connected to the printing unit, and in particular to a procedure of removal of causes of suspension of the individual units.
2. Description of the Related Art
Conventionally, various printing systems that include a printing unit for performing a printing process and a post-processing unit and/or a pre-processing unit connected to the printing unit are proposed.
Examples of the post-processing unit connected to the printing unit may include: a bookbinding unit, which performs case binding using printing paper sheets subjected to printing at the printing unit; an enclosing/sealing unit, which makes an envelope using a printing paper sheet subjected to printing and encloses and seals an inner paper sheet (letter) in the envelope to form a sealed letter; a stapler unit, which staples a bundle of printing paper sheets subjected to printing, etc. An example of the pre-processing unit may include a high capacity feeder unit, which is capable of feeding a large amount of printing paper sheets to the printing unit.
When paper jam occurs at the post-processing unit, for example, in the printing system including the units as described above, operations of the post-processing unit are suspended, and operations of the printing unit and the pre-processing unit are also suspended. With respect to the printing unit and the pre-processing unit, if paper jam also occurs at these units along with the paper jam at the post-processing unit, operations of the printing unit and the pre-processing unit are naturally suspended. However, the operations of the printing unit and the pre-processing unit are suspended even when no paper jam occurs at these units since the operations of the post-processing unit cannot be proceeded.
Then, causes of suspension at these units are removed by removing the paper jam at the post-processing unit, and removing printing paper sheets left on the conveyance path in the printing unit and/or the pre-processing unit.
On the other hand, when the operations of the units in the printing system are suspended, as described above, it is necessary to perform a preparation operation (warming-up operation), which is unique to each unit, after the cause of suspension at each unit is removed and before the system is recovered to start the next cycle of normal operation. The preparation operation begins at the point of time when the cause of suspension at each unit is removed.